The present invention is directed to an auxiliary presser foot mechanism for a sewing machine and more specifically to a cam operated auxiliary presser foot for pressing previously formed stitches against the throat plate during the tensioning of a new stitch to prevent puckering.
In a conventional sewing machine, the feed dog is projected slightly above the throat plate when the thread takeup lever is located at a position just before the top dead center position. At this time, a workpiece, including previously formed stitches is pressed onto the throat plate by the conventional presser foot. The force applied onto the workpiece from the presser foot is not concentrated on the previously formed stitches. Thus, previously formed stitches are subjected to excessive tension by the thread takeup lever during the formation of successive new stitches with the result that seam puckering or work shrinkage occurs upon completion of the sewing operation.